1.1 These test methods cover accelerated determination of the resistance of porcelain enamel coatings on aluminum alloys to spalling from exposure to moisture or weathering. Method A, using a 5% solution of ammonium chloride, requires 96-h immersion while Method B, using a 1% solution of antimony trichloride, is completed after 20 h of immersion. The spalling tendency is evaluated by the same criteria in both methods. While either method is suitable for magnesium silicon alloys, such as 6061, Method B is preferred for simple alloys or commercially pure aluminum, such as 1100.

1.2 The methods appear in the following order: